1. Field of the Invention
This invention relates in general to automatic vending machines for dispensing food products and similar articles. More particularly, this invention relates to a vending machine of the helical coil type having means for dispensing relatively thin and small products, e.g. gum and mint packages.
2. Description of the Prior Art
Various vending machines are known which may be generically referred to as helical coil vending machines or, alternatively, as spiral vendors. Such machines usually comprise a housing in which a plurality of shelves are slidably mounted. Each shelf usually includes a plurality of elongated helical coils which run from one side of the shelf to the other (e.g. from front to back). A plurality of food products to be dispensed are received between the adjacent convolutions of the coils and are dispensed over the front edge of the shelf as the coil is rotated. The coils are often received between side members or walls such that each coil lies in a product receiving trough or channel.
Most helical coil vending machines are adapted to dispense food products of certain sizes. These food products include bags of potato chips, pastry products, and other types of so-called "snack products". It has been the practice in the art to use different sized helical coils and adjustable product guide members in the same vending machine to accomodate variations in the size of the food products being dispensed. Even with such a feature, the coils and channels in most helical coil vending machines are not suitable for dispensing very small food products, such as gum and rolled mint products. These types of food products have conventionally been dispensed by an entirely separate dispenser which is included as part of the vending machine. However, this is disadvantageous if the cost of the vending machine is an important consideration since it is relatively expensive to provide a totally separate dispenser for gum and mint products.
Vending machine manufacturers have attempted to solve the above-identified problem by devising ways in which gum and mint products can be vended using helical coils. This has generally been accomplished by using an elongated divider member between the convolutions of the coil to decrease the width of the product receiving channel. In effect, this forms two small product receiving channels at either side of the coil in which gum and mint products can be effectively received. This approach of using an axial divider is disclosed in U.S. Pat. No. 3,929,255 to Wittern et al and U.S. Pat. No. 3,935,966 to Pitel et al.
Although the above-mentioned devices allow gum and mint products to be dispensed using helical coils, the use of an axial separator or divider member through the convolutions of the coil presents certain problems. For one thing, it can be difficult to secure the axial separator inside the coil convolutions. In addition, if the coil sags or otherwise contacts the separator there is always the possibility that the separator could jam or interfere with the rotation of the coil. Furthermore, since the axial separator divides the coil into two product receiving channels for each convolution, to vend only one product at a time it is necessary that the coil be rotated through only one half of a revolution. This requires that there be some means for controlling the operation of the coil rotating motor such that the coil can be rotated a full revolution when vending normal sized products or half a revolution when vending gum and mint products. Thus, the axial separator system cannot be used in many machines where the coil rotating motors are designed to rotate only through one revolution during each operation of the motor.